# massprop_torso: Torso and leg mass properties In AvInertia: Calculate the Inertial Properties of a Flying Bird

## Description

Calculate the moment of inertia of a head modeled as a solid cone

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```massprop_torso( m_true, m_legs, w_max, h_max, l_bmax, w_leg, l_leg, l_tot, CG_true_x, CG_true_z, start, end ) ```

## Arguments

 `m_true` Mass of the torso and legs - no tail (kg) `m_legs` Mass of the legs only (kg) `w_max` Maximum width of the body (m) `h_max` Maximum height of the body (m) `l_bmax` x location of the maximum width of the body (m) `w_leg` width of the body at leg insertion (m) `l_leg` x location of the leg insertion point (m) `l_tot` length of body from clavicle to beginning of the tail (m) `CG_true_x` x location of the CG for the torso and legs, origin is at the VRP, measured positive if aft of the VRP (m) `CG_true_z` z location of the CG for the torso and legs, origin is at the VRP (m) `start` a 1x3 vector (x,y,z) representing the 3D point where torso starts. Frame of reference: VRP | Origin: VRP `end` a 1x3 vector (x,y,z) representing the 3D point where tail ends. Frame of reference: VRP | Origin: VRP

## Value

This function returns a list that includes:

• Ia 3x3 matrix representing the moment of inertia tensor of the torso and leg composite body

• CGa 1x3 vector representing the center of gravity position of the torso and leg composite body

• ma double that returns the mass of the torso and leg composite body

## Warning

Parallel axis theorem does not apply between two arbitrary points. One point must be the object's center of gravity.

Christina Harvey

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31``` ```# refer to the vignette library(AvInertia) # load data data(dat_id_curr, package = "AvInertia") data(dat_bird_curr, package = "AvInertia") data(dat_feat_curr, package = "AvInertia") data(dat_bone_curr, package = "AvInertia") data(dat_mat, package = "AvInertia") data(clean_pts, package = "AvInertia") # 1. Determine the center of gravity of the bird's torso (including the legs) dat_torsotail_out = massprop_restbody(dat_id_curr, dat_bird_curr) # 2. Calculate the inertia of the flight feathers about the tip of the calamus feather_inertia <- compute_feat_inertia(dat_mat, dat_feat_curr, dat_bird_curr) # 3. Determine the center of gravity of one of the bird's wings dat_wing_out = massprop_birdwing(dat_id_curr, dat_bird_curr, dat_bone_curr, dat_feat_curr, dat_mat, clean_pts, feather_inertia, plot_var = 0) # Visualize the center of gravity of each wing component in the x and y axis dat_wing_out = massprop_birdwing(dat_id_curr, dat_bird_curr, dat_bone_curr, dat_feat_curr, dat_mat, clean_pts, feather_inertia, plot_var = "yx") # or the y and z axis dat_wing_out = massprop_birdwing(dat_id_curr, dat_bird_curr, dat_bone_curr, dat_feat_curr, dat_mat, clean_pts, feather_inertia, plot_var = "yz") # 4. Combine all data and obtain the center of gravity, moment of inertia # and principal axes of the bird curr_full_bird = combine_inertialprop(dat_torsotail_out,dat_wing_out, dat_wing_out, dat_id_curr, dat_bird_curr, symmetric=TRUE) ```

AvInertia documentation built on July 22, 2021, 9:08 a.m.